1. Field of the Invention
The primary object of the invention is to provide a device for reflecting the electromagnetic waves and a method for polarized construction of said device.
2. Description of the Prior Art
In modern radar systems, specialized channels are incorporated for collecting additional items of information and it is essential to separate the electromagnetic waves belonging to different channels. In antennas of the Cassegrain type, it is a known practice to use crossed polarizations for the various channels. For example, a principal channel operates with horizontal rectilinear polarization whilst a supplementary channel operates with vertical rectilinear polarization. Separation at the receiver takes place at the auxiliary reflector of the Cassegrain antenna which is reflecting for one polarization and transparent for the other. In the prior art, reflectors of this type were constructed by making use of parallel wires. In this design, the wires were embedded in a low-loss dielectric or constituted a grating. The auxiliary reflector of known type was neither perfectly transparent for one channel nor perfectly reflecting for the other. Theoretically, the system in fact operates only in the principal planes, namely the horizontal plane and the vertical plane.
The device in accordance with the present invention is made perfectly reflecting for one of the polarizations. Thus the incorporation of a supplementary channel in an existing radar system does not cause any disturbance in the operation of this latter. It must be pointed out, however, that the reflector in accordance with the invention is not perfectly transparent to electromagnetic waves transmitted over the supplementary channel.